Automatic-tape-dispensing guns (xe2x80x9cATGxe2x80x9d) are well known. These guns are used to lay down a double-sided adhesive that is used to mount or bond two articles together. Such adhesive can have opposing sides of the same or varying tack and/or adhesion.
Currently, most of the ATG""s use rolls of tape that are 36 yards long. These rolls have a standard outer diameter of approximately 3.1875 inches when wound on a standard 1.375 inch outer diameter core. In a normal operation, one may use several of these rolls of tape in a given day. During each changeover, each roll of tape must be individually threaded in the ATG. This is a time consuming process that results in lost productivity.
Previous attempts to store greater lengths of tape on rolls of a standard outer diameter have failed in that thinner tape has a thin release-liner that easily breaks, or the adhesive layer is to thin to allow for an acceptable application.
Although ATG tape rolls of 60 yards in length exist such rolls have a standard outer diameter of approximately 4.3125 inches. Because the 60 yard rolls have an increased outer diameter, a specially sized gun such as the one manufactured by 3M(copyright) Corporation of Minneapolis, Minn., is required to use them. The purchase of this gun requires an extra investment on the part of the tape user.
There is a long felt need to develop an ATG tape that allows for a greater length of tape to be stored on rolls having a standard outer diameter. Therefore, a tape capable of being used in a standard size ATG that is able to be wound so as to provide for a greater length of tape per roll would be an important improvement in the art.
An object of the invention is to provide a double-sided tape for an automatic dispensing gun that overcomes some of the problems and shortcomings of the prior art.
Another object of the invention is to provide a double-sided tape for an automatic dispensing gun that is capable of being rolled so that nearly twice the length of tape is capable of being used in existing automatic tape dispensing gun.
Yet another object of the invention is to provide a double-sided adhesive transfer tape for an automatic dispensing gun.
Still another object of the invention is to provide a carrier supported double-sided tape for an automatic dispensing gun where the tape utilizes a liner having a thickness no greater than 2 mils. How these and other objects are accomplished will become apparent from the following descriptions and from the drawings.
The invention involves a roll of tape for an automatic tape gun. The tape is comprised of an adhesive layer having a liner-side surface and an exposed-side surface. A release-liner adheres to the liner-side surface of the adhesive layer. The invention involves the selection of the thickness of the adhesive-layer and the release-liner such that the ratio of tape length to roll diameter on a standard 1.375 inch outer diameter roll core where the tape roll has a standard outer diameter of approximately 3.1875 inches, is substantially greater than about 400:1, whereby tape of extended length is usable on standard tape guns thereby minimizing the number of tape-roll changeovers.
In one embodiment of the invention, the ratio of tape length to roll diameter is greater than about 500:1. In a preferred version of this embodiment, the ratio of tape length to roll diameter is greater than about 550:1.
The release liner used in the tape involved in the invention has a thickness no greater than 2 mils. While no specific material is required for the liner, in a preferred embodiment, the release liner is a polymeric film such as polypropylene, polyester, nylon or polystyrene. This preferred liner also has a thickness no greater than 2 mils. It is also noted that the tape is capable of being wound around the roll core in a conventional manner or it may be what is known as reverse wound (i.e., the release-liner faces the inner core).
In one embodiment of the invention, the adhesive layer may be what is known in the art as an unsupported adhesive layer while yet in another embodiment, the adhesive layer may be reinforced on one or both side surfaces. In a specific version of such embodiment, glass beads, or fibers of glass, pulp, paper and the like may be used to reinforce the adhesive.
While it is preferred that both of the adhesive surfaces are of the same tack and adhesion, those skilled in the art will recognize that it is possible to construct the tape with one surface having a stronger tack and/or adhesion than the other surface without departing from the spirit or scope of the invention.
In another embodiment of the invention, the adhesive layer includes a carrier having first and second sides with each side having adhesive thereon. The first-side adhesive forms the liner-side surface of the adhesive layer while the second-side adhesive forms the exposed-side surface.
The thickness of the carrier is less than about xc2xd mil. Although the carrier can be made of various materials including paper, tissue and the like, in a preferred embodiment of the invention, the carrier is made of a polymeric film.
In still another embodiment of the invention, the adhesive-layer thickness and the release-liner are selected such that the ratio of tape length to roll diameter on a standard 1.375 inch outer diameter roll core where the tape roll has a standard outer diameter of approximately 4.3125 inches, is substantially greater than 500:1. In a specific version of such embodiment, the ratio of tape length to roll diameter is greater than about 600:1 while in a more preferred version, the ratio is greater than about 800:1.
In yet another embodiment of the invention, the adhesive-layer thickness and the release-liner are selected such that the ratio of tape length to tape thickness for a one-inch length of tape is substantially greater than about 195:1. In a specific version of such embodiment, the tape length to tape thickness ratio is greater than about 270:1 while in a more specific version the length to thickness ratio is greater than about 370:1.
The invention also involves a method of manufacturing a roll of tape for use in an automatic-tape gun. Such method is comprised of the steps of: (1) preparing an adhesive layer having a liner-side surface and an exposed-side surface; (2) attaching a release-liner having a thickness of 2 mils or less to the liner-side surface of the adhesive; and (3) winding the film release-liner around a core.